1. Field of the Invention
The present invention relates to a guillotine cutter provided with a pressing block for pressing a sheet bundle or the like to be cut to a sheet bundle supporting table.
2. Description of the Related Art
A conventional guillotine cutter 11 is provided with a rectangular sheet bundle supporting table 3 fixed to a frame 2, and a guillotine cutter blade 4 extending along one line of the sheet bundle supporting table 3 and arranged for vertical movement, as shown in FIGS. 4A and 4B. The guillotine cutter 11 is further provided with a pressing block 15 for pressing the sheet bundle 10 supported on the sheet bundle supporting table 3 to the sheet bundle supporting table 3, and a pressing block driving mechanism 16 designed to vertically move the pressing block 15.
The pressing block driving mechanism 16 has rods 161,161. One ends of the rods 161,161 are coupled to the pressing block 15, and the other ends thereof are coupled to one ends of swing arms 63,63. The swing arms 63,63 are can be swung around a horizontal axis 63a fixed to the frame 2. The pressing block driving mechanism 16 further comprises a vertically movable moving plate 64 which supports the other ends of the swing arms 63,63 in such a manner that the swing arms 63,63 can freely swing, and a feed screw 65 extending in a vertical direction and screwed with the moving plate 64. Further, the pressing block driving mechanism 16 is provided with a pulley 66 fixed to a lower end of the feed screw 65, first and second servo motors 168a and 168b driving the pulley 66 through a belt 67, and a controller 169 controlling the servo motors 168a and 168b. 
The first servo motor 168a is a low-power servo motor for loading a small pressing force, for example, about 50 kg weight to the sheet bundle 10. On the other hand, the second servo motor 168b a high-power servo motor for loading a large pressing force, for example, about 2 ton weight to the sheet bundle 10. The servo motors 168a and 168b can be driven alternately.
In accordance with this guillotine cutter 11, the sheet bundle 10 is pressed to the sheet bundle supporting table 3 by the small pressing force by using the low-power servo motor 168a while temporarily holding by a hand of worker, thereby temporarily fixing. The sheet bundle 10 is pressed against the sheet bundle supporting table 3 by the large pressing force by using the high-power servo motor 168b after pulling back the hand of worker to a safe region. In other words, in accordance with the guillotine cutter 11, there is no risk that the hand of the worker is crushed by the large pressing force, and it is possible to work safely.
However, it is necessary to provide two various servo motors that is the high-power servo motor and the low-power servo motor, so that high cost was required. Further, the control mechanism of both the servo motors was complicated. In this case, it is desired that the large pressing force of about 2 ton weight and the small pressing force of about 50 kg weight are generated by using a single servo motor, however, since a power gap between both the pressing forces is very large, it was almost impossible to achieve this.